This is a dose ranging study of d-sotalol (a class III antiarrhythmic) for sustained VT/VF patients. The initial dose-ranging phase is double blinded, randomized to one of several doses. If the assigned range is tolerated but not effective, an open-label higher dose is allowed. If both effective (judged by EP study) and tolerated, long term out-patient follow will ensue. Rendering the patient non-inducible in the EP lab is the efficacy end-point.